LeetCode 58. Length of Last Word

Given a string s consists of upper/lower-case alphabets and empty space characters ' ', return the length of last word in the string.

If the last word does not exist, return 0.

Note: A word is defined as a character sequence consists of non-space characters only.

Example:

Input: "Hello World"
Output: 5


这道题简直太简单，面试都考这样的就好了，需要求最后一个单词的长度，如果不存在最后返回0。而且s只存在字母和空格，不存在其他的字符，只需要从后向前遍历数字符就可以了，代码如下：

class Solution {
public:
    int lengthOfLastWord(string s) 
    {
        int len = 0, tail = s.length() - 1;
        while (tail >=0 && s[tail] == ' ')
            tail--;
        while (tail >=0 && s[tail] != ' ')
        {
            tail--;
            len++;
        }
        return len;
    }
};